The pseudo-binary Na2B4O7-[Na3AlF6-TiO2](11) system has been investigated at room temperature by means of X-ray diffraction, IR, Raman, and UV-vis spectroscopies. Evolution of the different spectra with Na2B4O7 and TiO2 contents evidenced the breaking-up of the large borate rings in favor of small borate units, the diminution of the B-IV fraction, and the partial substitution of oxygen by fluorine with the formation of oxyfluoride species. Two domains of compositions are described: a TiO2-rich region with 20-50% Na2B4O7 with the lowering of boron coordination and formation of Ti(O,F)(6) units and a TiO2-poor region with 60-90% Na2B4O7 where the Na3AlF6 modifier behavior is predominant. The enhanced modifier effect of [Na3AlF6-TiO2](11) in comparison with pure Na3AlF6 on the vitreous network of Na2B4O7 consists of fluorine preference for binding to higher strength cations, Ti4+, over Al3+ and Na+ respectively, when TiO2 addition exceeds 5 wt %.